Specifications:EX lens series denotes excellence of engineering and new technology.
Compact and lightweight zoom despite large F2.8 aperture.
Excellent correction for various types of aberration provided by one SLD (Special Low Dispersion) glass element and two aspherical lenses.
Super Multi Layer (SML) coating reduces flare and ghosting from which digital cameras tend to suffer.
F2.8 large aperture standard zoom lens designed specially for use with digital SLR cameras.

The characteristics of digital SLR cameras were taken into consideration when designing the lens power layout. The new advanced lens design corrects various aberrations. This lens provides the utmost correction against lateral chromatic aberration which is a serious problem for digital SLR cameras.

This lens is specially coated to get the best color balance whilst cutting down flare and ghost caused by reflections from the digital image sensor and lens. It has excellent correction for vignetting and superior peripheral brightness is ensured.

A Special Low Dispersion (SLD) lens and two aspherical lens elements provide excellent correction for all types of aberrations. The design produces a compact and lightweight, yet robust, construction with an overall length of 84.1mm (3.3in.) and maximum diameter of 74.1mm (2.9in.) and weight of 445g (15.6oz).

This lens has a minimum focusing distance of 28cm (11in.). It is equipped with inner focusing system. The non-rotating front lens element makes the lens suitable for using its petal-type lens hood and circular polarizing filters.

Bought lens second hand. Took a leap of faith that the images posted by seller were not true reflection of its potential. My lens is the hsm version and I could not be happier with the images I am producing.

Quite a performer at a third of the price compared to the Nikkor 17-55mm f/2.8. The lens has the weight and a tight feel. Sigma's EX finish is also quite pleasant. However, their quality control needs some improvement. I have had/used my particular copy for over three years and although I have gotten quite a bit satisfactory photos, it is pretty obvious that there are some shortcomings.

The edges at f/2.8 is quite soft at all focal lengths but especially on the wide end. Stopped down would improve the performance. My particular copy has slight front focus that does not affect the photo too much but the right side is soft compared to the left which led to some fuzzy photos although focused correctly.

Even with the f/2.8, AF accuracy and speed is not good at low-light situations. The lens would go through the entire focal length range and hunts before failing to focus. Even if it did focus, it takes quite a few seconds that if the subject is a moving child, there goes the shot.

Overall it is a good lens to buy on a small budget but its performance leaves more to be desired. If budget is tight, I would suggest getting a faster prime such as the 35mm f/1.8G, f/2D; 50mm f/1.8G, f/1.4D for sharpness and speed. Zoom is useful, but I prefer sharper photos captured.

Dec 4, 2009

jz77OfflineImage Upload: Off

Registered: May 3, 2009Location: PolandPosts: 0

Review Date: May 3, 2009

Recommend? yes |
Price paid: $430.00
| Rating: 9

Pros:

iq for the price, colors build quality, handling

Cons:

focus in dark

I've had this lens for over 2 years with two canon 400d bodies and took lots of photos I'm very happy with. Once thought about selling just because whatever, but made my mind that there are no reasons and I'll use it more and I don't regret, it's great as a walkaround and for tourism, good colors. Went on trips with that and it's neat for that.

Don't know if there's some zoom with this light in this price that would beat it, haven't tried the Tamron though. The iq in the corners is not very good so don't know if it'd work for pro shoots, but overally I think it meets the iq/price factor very well and you'll be happy with it.

It has some problems with focusing in dark, it tends to go through all the range and stop on some random place, after a few tries and a bit of light it may finally get near the spot.
The noise, well, you can get used to it, it's for shooting pics not listening to, and it's not as annoying as in some other sigmas I've had.

I bought this lens after selling my 17-40mm L series Canon lens. I wanted a faster lens and didn't mind downgrading in build quality a bit. I'm glad I did this as this lens is very very good for the money and I can see it being in my bag a lot!

Its focusing isn't as fast as the 17-40 but it is just as accurate. The lens is nice to hold and I recommend it to anyone with a 1.6x sensor as a general purpose lens! I saw no point in forking out £750+ for a Canon EF-S 17-55mm f/2.8 when this was £260. I don't need IS as I have steady hands and the subjects I photograph are usually the ones moving!

May 3, 2009

saakalOfflineImage Upload: Off

Registered: Feb 17, 2009Location: EstoniaPosts: 0

Review Date: Feb 17, 2009

Recommend? yes |
Price paid: Not Indicated
| Rating: 10

Pros:

Vivid colours and sharp as a scalpel!

Cons:

Could have HSM

Just buy one!

Feb 17, 2009

timontarioOfflineImage Upload: Off

Registered: May 30, 2008Location: CanadaPosts: 163

Review Date: Dec 6, 2008

Recommend? yes |
Price paid: Not Indicated
| Rating: 10

Pros:

Quick focus, beautiful bokeh & great IQ

Cons:

None.

I've had this lens for about 24 hours, and have popped off about 500 shots with it. It's great. I had the 17-70 2.8-4.5 - but found that I was getting frustrated with the loss of a stop & third at the long end. Traded it in at Henry's for half back towards this one.

Bokeh at 50mm is nice, low light performance is great too.

Hunts for focus in very low-light -=- but then again, I can't see that great at night either -- why expect the lens to change that ;-)

So far - My images have been SUPER crisp. I'm extremely satisfied.

Dec 6, 2008

Joseph N. HallOfflineImage Upload: Off

Registered: Dec 31, 2007Location: United StatesPosts: 0

Review Date: Sep 2, 2008

Recommend? yes |
Price paid: Not Indicated
| Rating: 10

Pros:

Lightweight, well built, fast, image quality excellent.

Cons:

Slight droop; focus ring rotates (no HSM).

At this price, and in general, I can't find anything major to complain about with this lens. I actually have the SA (Sigma mount) version, but it's electronically equivalent to the EF - Sigma uses the EOS signaling protocol, so I'm assuming that the lens will perform and handle similarly on both bodies.

At a constant f/2.8, it's fast. It's light. It handles well. Seems solid like my other EX lenses. There's not much to complain about image quality wise. I'd consider the IQ "A-" to "A" depending on focal length and aperture. It performs well wide open.

There's a slight tendency for the barrel to droop when the lens is pointed straight down (or up). Not really a problem. It would be nice if the lens had HSM, but the rotating focus ring doesn't pose much of a handling problem. Basically, the lens takes good pictures, is an all around good performer, and is reasonably priced.

Sep 2, 2008

AlanuOfflineImage Upload: Off

Registered: Mar 8, 2008Location: CanadaPosts: 578

Review Date: Aug 24, 2008

Recommend? yes |
Price paid: Not Indicated
| Rating: 9

Pros:

Wide open the images are very useable, Fast AF, stopping down to f3.5 has very impressive IQ, great bokeh, excellent performer for the price range.

Cons:

Marginal zoom creep. Hunting may occur in very low light situations. Good build but no comparison to Canon's "L" series.

I would consider this lens to be a pleasant suprise. You may find negative reviews on this lens but make a note it may be of the older versions of this focal range.

My copy has provided me excellent IQ. Keep in mind $$ to IQ ratio. Looking at photos taken with my 24-70L I feel the Sigma 18-50EX holds its own in terms of sharpness and colour rendition. The sigma may have a hint of more warmth to the image.

If you want an "L" lens in this focal range there really isn't any. The non "L" EF-S 17-55 IS is double the price but faster AF and dead on accurate in low light. The Sigma 18-50EX is marketed for a lower budget, however IMO its no slouch.

This lens is dedicated for the crop camera bodies so take that into condsideration in your purchase. If your moving onto full frame this lens isn't for you.

I chose the Sigma vs the more expensive EF 17-40 f4 L because I wanted faster glass. IMO the 18-50EX equals to this particular "L"lens but has the edge for nicer bokeh.

I highly recommend this lens to any hobbyist that demands high IQ at an affordable price. For photogs getting paid for their work the EFS 17-55 IS will provide more keepers in low light.

Like anything post processing is a photographers best friend. Minimal tweeks maybe required but this also applies to higher end lenses aswell.

This lens will remain in my gearbag. It compliments my other lenses well (24-70L, 70-200 2.8IS, 85 1.8 etc) without compromising IQ.

Good performance wide open, very sharp stopped down, focuses quickly and accurately, good build quality, excellent lens. That is if you get a good copy.

Cons:

Shoddy quality control (I went through 4), little too much damping on zoom ring, inconsistent fit and finish.

I went through 4 of these lenses (Macro version) to get a good copy, so make sure you buy it from somewhere with a good exchange policy.

1st lens had extremely poor focus calibration and was exchanged.
2nd lens had slight front focus and was sharper at the edges than in the center, and slight, but noticeable decentering. This one was borderline acceptable.
3rd lens had obvious decentering where a large portion of one corner was completely smeared. Focus was great though.
4th and final lens is great, with no noticeable decentering and excellent focus.

I may be a little more nitpicky than the average person though, and I think the 2nd copy would probably have been acceptable to some.

Fit and finish not consistent between copies. Two had slight play in the zoom ring, 3 previous copies had stiff focus/lock switches.

Build is overall good, with a nice finish, solid feel, and very little barrel wobble. Comes with a nice case and hood.

Image quality on the keeper lens is excellent. Colors are a bit different from Canon lenses, but easily corrected with custom white balance. Wide open -- images are sharp, and as expected, softness is visible in corners. The lens is very sharp past f4, corner to corner. Vignetting is visible at f2.8 at the wide end of the zoom, but very low stopped down past f4. Vignetting is virtually gone at the longer end.

Focus speed is quick, accurate, and fairly quiet (assuming it is calibrated well). There is a light buzzing noise when autofocusing. Accurate manual focusing is difficult due to the short rotation range and undamped ring.

Overall a nice step up from the kit lens, and an affordable large aperture zoom. If only Sigma could get their QC up to snuff.

I love this lens, it and it's 150mm Macro brother are the only lenses I need.

Fast and quiet HSM, near-macro close focus, high resolution contrasty images, and VERY sharp above f4. The distortion is moderate below 24mm and undetectable above 35mm. The bokeh at 35mm+ is great at large aperatures. And it feels well built, no zoom creep and good focal dial resistance.

But what the hell were Sigma thinking having the focus ring move during AF? A lens this short and heavy requires you to grab the damn ring to hold the camera and when the ring moves you lose shots. And Sigma needs to start using center-pinch lens caps, you can't attach their cap with the hood on.

F2.8 is usable with good centre sharpness. Very sharp between F5.6 and F11 across the whole zoom range. Very good build quality. A high quality kit lens with true F2.8.

Cons:

Focus ring rotates during autofocus. Don't know why the design does not follow other EX lenses such as the 10-20 with a distance window. No HSM (but they released the HSM version for Nikon!)

Always felt my 24-105 L is not wide enough. Recently got the macro version for my Canon 350D. The sharpness is comparable to Canon L glass. Excellent sharpness at both centre and border when stopped down. Color and saturation are good. But Canon L is a bit better, fair enough. Build quality better than Tamron. No front/back focus issue, fast and accurate focus. Very satisfied with the overall performance. I need a standard kit lens with very good wide angle performance and large aperture, this is the one. Will be in my camera most of the time.

Something to mention, the 18mm performance is much much better than the 17mm of my first Canon lens, the 17-85 IS (of course sold).